The US Move in

During the late sixties, the Sihanouk government came under severe stress, caused 60's. The US had been wooing the military US, and the internal conflicts between the new elite in Cambodia and the workers and peasantry.

The increasing urgency of the situation of the US in South East Asia, as they were becoming increasingly bogged down in Vietnam meant that the Sihanouk regime in Phnom Penh had to be toppled, not because it was necessarily a progressive country, but because to win a victory in Vietnam, the Americans had to gain control of Cambodia.

As well as this, the Americans were also getting jittery over Sihanouk's close relations with countries like China and the DPR of Korea.